1. Field of the Invention
The present invention relates to a recording method for performing printing on the surface of a material to be printed made of a nonabsorbent material which does not absorb ink, such as aluminum.
2. Description of the Related Art
A conventional recording method for drawing on an aluminum surface is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 11-326548. In this publication, the dial of a watch is made of aluminum and a receiving layer is formed on the surface thereof. A coloring material (pigment) is applied onto the receiving layer so as to print characters and the like thereon.
In the above recording method, pigment is used as the coloring material. Since pigment particles are large, they are not thoroughly received by the receiving layer and are not fixed easily thereon.
Furthermore, in the above recording method, ink droplets of a plurality of colors are appropriately superimposed on the receiving layer so as to produce a specific color. When the ink droplets are superimposed, they spread (blur) on the aluminum surface, and therefore, a clear image cannot be obtained.
FIG. 8 is an explanatory view showing a case in which a drawing function using a printer head is performed on a substance made of a nonabsorbent material, which does not absorb ink droplets. When an ink droplet 11a is ejected from a first nozzle 11 of a printer head 10 and an ink droplet 12a is then ejected from a second nozzle 12 to the same position, both ink droplets 11a and 12a are mixed and spread (blur) with the passage of time, as shown in section C.
The present invention has been made to overcome the above problems, and an object of the invention is to provide a recording method which reduces blurring and makes it easier to fix ink droplets in position on a printing surface.
(1) In a recording method according to an aspect of the present invention, printing is performed on the surface of a substance made of a nonabsorbent material that does not typically absorb an ink droplet. Preferably, the substance is heated while being printed upon. Since printing is performed on the surface while heating the surface, moisture contained in the ink droplet is evaporated and adsorption of the ink droplet onto the nonabsorbent material is facilitated, thereby reducing the printing time. For this reason, the ink droplet is restrained from spreading, blurring is prevented, and a clear image can therefore be obtained.
(2) In a recording method according to another aspect of the present invention, the nonabsorbent material in the above enumerated paragraph (1) is a soft alumite. Since printing is performed while heating the soft alumite in this invention, not only drying of the ink droplet but also adsorption of the ink droplet into a porous layer formed on the surface of the soft alumite is speeded up, and the ink droplet is fixed in position in a short time. For this reason, the ink droplet is restrained from spreading and blurring is prevented.
(3) In a recording method according to a further aspect of the present invention, a soft alumite is produced by forming an oxide film on an aluminum surface, and printing is performed on the surface of the soft alumite while heating the soft alumite. Since printing is performed on a porous layer formed on the surface of the soft alumite in this invention, an ink droplet can easily enter minute holes of the porous layer and ink blurring can be prevented. Furthermore, since printing is performed while heating the soft alumite, in a manner similar to the above, adsorption of the ink droplet to the porous layer is speeded up, and the ink droplet is fixed in a short time. For this reason, the ink droplet is restrained from spreading and blurring is prevented. In particular, since the size and depth of the holes of the porous layer formed in the soft alumite are optimized for this application, the above advantages are pronounced.
(4) In a recording method according to a further aspect of the present invention, recited in enumerated paragraph (3), printing is performed with a dye-based ink. Since particles of the dye-based ink are small, they easily enter the minute holes of the porous layer. Furthermore, since the dye-based ink is subjected to ion separation, they are fixed in the holes of the porous layer by molecular adsorption or ion binding. For this reason, the ink droplet is fixed firmly, and chemical resistance is increased. Since absorption by molecular adsorption or ion binding is speeded up by the heat treatment and fixing is completed in a short time, the ink droplet is restrained from spreading. This also prevents blurring.
(5) In a recording method according to a further aspect of the present invention, a porous layer is formed on the surface of a nonabsorbent material which does not absorb an ink droplet, and printing is performed thereon with a dye-based ink. Since particles of the dye-based ink are small, they easily enter minute holes of the porous layer, and this prevents blurring. Furthermore, since the ink droplet is adsorbed by molecular adsorption or ion binding and is fixed firmly, chemical resistance is increased.
(6) In a recording method according to a further aspect of the present invention, a soft alumite is produced by forming an oxide film on an aluminum surface, and printing is performed on the soft alumite with a dye-based ink. Since printing is performed with the dye-based ink on a porous layer formed on the surface of the soft alumite in this invention, particles of the dye -based ink easily enter minute holes of the porous layer, and blurring can therefore be prevented. Since the ink droplet is adsorbed by molecular adsorption or ion binding and is fixed firmly, chemical resistance is increased.
(7) In a recording method according to a further aspect of the present invention, printing is performed on a soft alumite with a dye-based ink. Since the soft alumite is used, blurring is prevented and chemical resistance is increased, as described above.
(8) In a recording method according to a further aspect of the present invention as recited in the above enumerated paragraphs (1) to (7), a sealing treatment is performed after printing. Since the ink layer is coated by sealing treatment, wear resistance is increased.
(9) In a recording method according to a further aspect of the present invention as recited in enumerated paragraphs (1) to (4), and (8), the heating temperature is preferably within the range of 30xc2x0 C. to 80xc2x0 C. In this invention, the lower limit temperature, at which the advantages are provided with respect to room temperature (20xc2x0 C. to 25xc2x0 C.), is set at 30xc2x0 C., and the upper limit temperature is set at 80xc2x0 C. in consideration of the decomposition temperature of the dye-based ink.
(10) In a recording method according to a further aspect of the present invention as recited in the above enumerated paragraphs (9), the heating temperature is preferably within the range of 30xc2x0 C. to 60xc2x0 C. The upper limit of the temperature is set to 60xc2x0 C. in consideration of the decomposition temperatures of some dye-based inks that are low.
(11) In a recording method according to a further aspect of the present invention in accordance with the above recording method (10), the heating temperature is preferably set to a range of 40xc2x0 C. to 50xc2x0 C. In this embodiment, the lower limit temperature, at which pronounced advantages are provided with respect to room temperature (20xc2x0 C. to 25xc2x0 C.), is set at 40xc2x0 C., and the upper limit temperature is set at 50xc2x0 C. in consideration of variations in decomposition temperatures of dye-based inks.
(12) In a recording method according to a further aspect of the present invention as recited in the above enumerated paragraphs (1) to (11), the printing operation is a color printing operation. Color printing is accomplished by superimposing ink droplets, which would typically lead to blurring, this invention, however, blurring can be prevented by the heat treatment. Moisture contained in the ink droplets is evaporated by heat treatment, and adsorption of the ink droplets into the nonabsorbent material is speeded up and is completed in a short time. This can prevent blurring.
(13) In a recording method according to a further aspect of the present invention as recited in the above enumerated paragraphs (1) to (12), the printing operation is performed by an ink-jet printer. In this invention, printing is performed on the nonabsorbent material by an ink-jet printer, which is a widely used printing apparatus.
(14) In a recording method according to a further aspect of the present invention as recited in enumerated paragraphs (1) to (4) and (8) to (13), the heating operation includes a partial heating operation with a laser. In this invention, the printing portion is subjected to partial heating with a laser. Such local heating leads to energy saving.
(15) In a recording method according to a further aspect of the present invention as recited in enumerated paragraphs (1) to (4) and (8) to (13), the heating operation includes a partial heating operation with infrared rays. In this invention, the printing portion is subjected to partial heating with infrared rays. Such local heating leads to energy saving.
(16) In a recording method according to a further aspect of the present invention as recited in above paragraphs (1) to (4) and (8) to (13), the heating operation is performed with a stroboscope. In this invention, the printing portion is instantaneously heated with a stroboscope. Such instantaneous heating leads to energy saving.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.